To optimize conducted performance from a transmitter, receiver or transceiver front end module (FEM), a matching network (matching network A) is often used between the FEM and an external antenna. Because conducted performance is usually measured in a 50 ohm system, the matching network is typically optimized towards the 50 ohm load associated with the external antenna. Other antennas considered for use as an internal antenna, however, may have optimum radiation performance at a different impedance than 50 ohms. A typical solution to this problem is to place a different matching network (matching network B) in series after matching network A to try to match for optimum radiation performance. However, the restriction of including matching network A may, in most cases, decrease the power delivered to the internal antenna compared to if a match is made directly between the FEM and the internal antenna.
For example, as shown in FIG. 1, FEM 100 may connect to external antenna 110 through matching network A 120 via a connector 130 placed in a first switching position 140. FEM 100 may connect to internal antenna 150 through matching network A 120 and matching network B 160 via connector 130 placed in a second switching position 170. Since matching network A 120 has been optimized towards the 50 ohm load of the external antenna, optimization of matching network B towards the load of internal antenna 150, that is different than 50 ohms, results in a decrease of power delivery to internal antenna 150.